Core Operating Principles

What are the principles underlying feeder operation, and what strategies are employed to achieve precise flow rate control and proportioning accuracy in plastics processing?

The purpose of continuous gravimetric feeding is to uniformly discharge process material at an accurately controlled weight-based rate (e.g., lb/hr or kg/min). This section introduces three operating principles typically employed in plastics processes to accomplish this purpose: Loss-in-Weight, Weigh Belt, and Weigh Meter feeding. A more detailed discussion of the issues and challenges these principles encounter is presented in the sections following this module (Focus on Material Handling, Focus on Weighing, and Focus on Control).

Also presented in this section are profiles of the two most common methods of blending multiple ingredients in plastics compounding and extrusion operations: Batch Blending and Continuous Blending.